Output member for a direct impact Hopkinson pressure bar

Patent metadata

Field	Value
Publication number	US-9778157-B2
Application number	US-201514967887-A
Country	US
Kind code	B2
Filing date	Dec 14, 2015
Priority date	Dec 22, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

An output member for a Direct Impact Hopkinson pressure bar includes an elongate tube portion and a disc-shaped cap portion. The tube portion has a first end and an opposite second end, while the cap portion includes a first face and an opposite second face. A circular stub protrudes from a center of the first face, and a circular cavity is formed in the second face. Each of the stub and the cavity is concentric with the cap portion, with a diameter of the cavity being greater than a diameter of the stub. The second face of the cap portion is positioned in intimate contact with the first end of the tube portion, with the cap portion being concentric with the tube portion.

First claim

What is claimed is:

1. An output member for a Direct Impact Hopkinson pressure bar, comprising:
an elongate tube portion comprising a first end and an opposite second end; and
a disc-shaped cap portion comprising a first face and an opposite second face,
wherein a circular stub protrudes from a center of the first face, a circular cavity is formed in the second face, each of the stub and the cavity being concentric with the cap portion, a diameter of the cavity being greater than a diameter of the stub, and the second face of the cap portion being positioned in intimate contact with the first end of the tube portion, with the cap portion being concentric with the tube portion.

2. The output member as claimed in claim 1 , wherein the diameter of the stub is between 0.8 and 0.95 of the diameter of the cavity.

3. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 2 .

4. The output member as claimed in claim 1 , wherein the diameter of the stub is approximately 0.9 of the diameter of the cavity.

5. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 4 .

6. The output member as claimed in claim 1 , the cap portion further comprising an axial length being defined between the first face and the second face, wherein a depth of the circular cavity is between 6 mm and 12 mm less than the axial length.

7. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 6 .

8. The output member as claimed in claim 1 , wherein a distal surface of the circular stub is faced with a facing layer.

9. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 8 .

10. The output member as claimed in claim 8 , wherein the facing layer is formed from a material selected from the group comprising steels and titanium alloys.

11. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 10 .

12. The output member as claimed in claim 1 , wherein the cap portion is formed from a material selected from the group comprising aluminum alloys and magnesium alloys.

13. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 12 .

14. The output member as claimed in claim 1 , wherein the elongate tube portion comprises an internal cushion at the second end.

15. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 14 .

16. A Direct Impact Hopkinson pressure bar comprising an output member as claimed in claim 1 .

Assignees

• Rolls Royce Plc

Inventors

• Macdougall Duncan Alexander Stuart
• Brown Kevin Anthony
• Jackson Matthew David
• White Roger

Classifications

• G01N3/02

  Details · CPC title

• G01N2203/0441

  with dampers or shock absorbing means · CPC title

• G01N3/307

  generated by a compressed or tensile-stressed spring; generated by pneumatic or hydraulic means · CPC title

• G01N3/30 Primary

  by applying a single impulsive force, e.g. by falling weight · CPC title

• G01N2203/0055

  using mechanical waves, e.g. acoustic · CPC title